Semiconducter device with filler to suppress generation of air bubbles and electric power converter

Abstract

A semiconductor device including: an insulating substrate having a conductor layer on the upper face and the lower face and a semiconductor element mounted on the upper conductor layer; a base plate bonded to the lower conductor layer; a case member surrounding the insulating substrate and bonded to the surface of the base plate to which the conductor layer bonded to the lower face; a first filler being a silicone composition filled in a region surrounded by the base plate and the case member; and a second filler being injected into a region below the first filler and surrounding a peripheral edge portion of the insulating substrate, whose height from the base plate is higher than the upper face and is lower than a bonding face between the semiconductor element and the upper conductor layer.

The invention claimed is: 
     
       1. A semiconductor device, comprising:
 an insulating substrate having a conductor layer formed on each of an upper face and a lower face of the insulating substrate, the conductor layer on the upper face including a plurality of conductor layers in a plurality of areas, at least one of the plurality of conductor layers on the upper face having a semiconductor element mounted thereon; 
 a base plate bonded to the conductor layer on the lower face; 
 a case member surrounding the insulating substrate and adhering to a surface of the base plate to which the conductor layer on the lower face is bonded; 
 a first filler being a silicone composition injected into a region surrounded by the base plate and the case member; and 
 a second filler being a silicone composition that is harder than the first filler, the second filler being injected into a region surrounding a peripheral edge portion of the insulating substrate and a region between the plurality of conductor layers so as to cover an entirety of the upper face of the insulating substrate in the region between the plurality of conductor layers, the second filler being injected into a region below the first filler, the second filler being injected into a region in which a height from the base plate is higher than the upper face and is lower than a bonding face between the semiconductor element and the conductor layer on the upper face. 
 
     
     
       2. The semiconductor device according to  claim 1 , wherein the second filler has a viscosity in a range from 0.5 Pa·s to 20 Pa·s. 
     
     
       3. The semiconductor device according to  claim 1 ,
 wherein a creepage distance of the insulating substrate exposed from the conductor layer is 1 mm or more, and 
 wherein a distance from the base plate to a surface portion of a lower face of the insulating substrate, which is filled with the second filler, is in a range from 0.3 mm to 1 mm. 
 
     
     
       4. The semiconductor device according to  claim 1 , wherein an interval between the case member and the insulating substrate is in a range from 2 mm to 10 mm. 
     
     
       5. The semiconductor device according to  claim 1 , wherein the second filler has a hardness in a range from 10 to 70 in Shore A hardness. 
     
     
       6. The semiconductor device according to  claim 1 , wherein the first filler has a hardness in a range from 20 to 100 in penetration. 
     
     
       7. The semiconductor device according to  claim 1 , wherein the insulating substrate includes a plurality of insulating substrates bonded on the base plate. 
     
     
       8. The semiconductor device according to  claim 7 , wherein an interval between the plurality of insulating substrates bonded on the base plate is in a range from 2 mm to 10 mm. 
     
     
       9. The semiconductor device according to  claim 1 ,
 wherein the first filler includes a silicone gel, and 
 wherein the second filler includes a silicone rubber. 
 
     
     
       10. An electric power converter, comprising:
 a main conversion circuit including the semiconductor device of  claim 1  and configured to convert power input to the main conversion circuit to output power obtained by the conversion; and 
 a control circuit configured to output a control signal for controlling the main conversion circuit to the main conversion circuit. 
 
     
     
       11. A semiconductor device, comprising:
 an insulating substrate having a conductor layer formed on each of an upper face and a lower face of the insulating substrate, the conductor layer on the upper face having a semiconductor element mounted thereon; 
 a base plate bonded to the conductor layer on the lower face; 
 a case member surrounding the insulating substrate and adhering to a surface of the base plate to which the conductor layer on the lower face is bonded; 
 a first filler being a silicone composition injected into a region surrounded by the base plate and the case member; 
 a second filler being a silicone composition that is harder than the first filler, the second filler surrounding a peripheral edge portion of the insulating substrate below the first filler in the region, the second filler being injected into a region in which a height from the base plate is higher than the upper face and is lower than a bonding face between the semiconductor element and the conductor layer on the upper face; and 
 a partition wall formed around an entire outer periphery of the insulating substrate, an inside of the partition wall being filled with the second filler. 
 
     
     
       12. The semiconductor device according to  claim 11 , wherein a distance from an end portion of the insulating substrate to the partition wall is smaller than an interval between the case member and the insulating substrate, and is in a range of 2 mm or more and less than 10 mm. 
     
     
       13. The semiconductor device according to  claim 11 , wherein the second filler has a viscosity in a range from 0.5 Pa·s to 20 Pa·s. 
     
     
       14. The semiconductor device according to  claim 11 ,
 wherein a creepage distance of the insulating substrate exposed from the conductor layer is 1 mm or more, and 
 wherein a distance from the base plate to a surface portion of a lower face of the insulating substrate, which is filled with the second filler, is in a range from 0.3 mm to 1 mm. 
 
     
     
       15. The semiconductor device according to  claim 11 , wherein an interval between the case member and the insulating substrate is in a range from 2 mm to 10 mm. 
     
     
       16. The semiconductor device according to  claim 11 , wherein the second filler has a hardness in a range from 10 to 70 in Shore A hardness. 
     
     
       17. The semiconductor device according to  claim 11 , wherein the first filler has a hardness in a range from 20 to 100 in penetration. 
     
     
       18. The semiconductor device according to  claim 17 , wherein an interval between the plurality of insulating substrates bonded on the base plate is in a range from 2 mm to 10 mm. 
     
     
       19. The semiconductor device according to  claim 11 , wherein the insulating substrate includes a plurality of insulating substrates bonded on the base plate. 
     
     
       20. The semiconductor device according to  claim 11 ,
 wherein the first filler includes a silicone gel, and 
 wherein the second filler includes a silicone rubber.